Amalgam gun

ABSTRACT

An air-driven plunger in an amalgam gun moves outwardly to force a known quantity of amalgam into a cavity. Upon reaching its outward limit, the plunger is caused to vibrate back and forth by automatic operation of valving. The vibrating plunger packs the amalgam in the cavity. An adjustment at an end of the gun opposite the plunger predetermines the amount of amalgam which the gun carries.

United States Patent Jochems [54] AMALGAM GUN [72] Inventor: Jozeph Roelof Jochems, 21 J.P. Coenlaan,

Vlaardingen, Netherlands [22] Filed: Jan. 16, 1970 [21] Appl. No; 3,469

[4 Feb. 15, 1972 Fraser ..32/60 X Primary Examiner-Robert Peshock Attorney-Littlepage, Quaintance, Wray and Aisenberg [57] ABSTRACT An air-driven plunger in an amalgam gun moves outwardly to [30] Foreign Application Priority Data force a known quantity of amalgam into a cavity. Upon reaching its outward limit, the plunger is caused to vibrate Jan. 22, 1969 Netherlands ..690106l back and forth by automatic operation of valving The vibrat ing plunger packs the amalgam in the cavity. An adjustment at [52] U.S.C| ..32/60 a end of the gun opposite the plunger predetermines the [51] Int. Cl ..A6lc 5/04 amount of amalgam which the gun carries.

58 F'eld fSe h ..222 389, 397, 60 I 1 10 Claims, 2 Drawing Figures 3 7 ea 5 6b 13 11 9 1s 1s 17 2 l I l l IIIIIIIIIIIIIIIII PAIENTEUFEB 15 m2 3,641,673

B W ATTORNEY;

AMALGAM GUN BACKGROUND OF THE INVENTION This invention relates to an amalgam gun for filling a cavity with amalgam or the like comprising a tubular housing, a rod which is movably mounted in side the housing with a plunger at one end, which plunger together with one end of the housing forms a storage chamber for accommodating a quantity of amalgam or the like from the outside, and means for displacing the plunger with respect to the housing. Such a gun is generally known in practice and is used by dentists to fill cavities in teeth or molars. The known amalgam guns comprise a tubular housing, one end of which is curved in shape. Within this end, the rod is flexible to be able to follow the curve in the tube. The remainder of the rod is rigid. These guns are operated by hand like an injection syringe. To this end the rigid rod extends beyond the housing and is provided with a pressing knob. A small quantity of previously prepared amal gam is placed in the filling opening of the housing in front of the plunger, which plunger is in the retracted position. Subsequently, the filling opening is placed over the cavity, while the plunger is pressed outwards until a small quantity of amalgam is transferred into the cavity. Subsequently, the amalgam first of all has to be compacted with an amalgam stopper or the like. Then the gun has to be refilled with amalgam, the amalgam has to be inserted into the cavity, compacted, etc. A large cavity may require a great many doses of amalgam. It will be obvious that filling a cavity in this way is a time-consuming operation.

It is not possible with the known amalgam gun to insert a large dosage of amalgam into the cavity in one operation, because in this instance the amalgam cannot be compacted sufficiently, while moreover a too great manual effort would be required.

SUMMARY OF THE INVENTION It is the object of the invention to furnish an amalgam gun which is driven by a pressure medium, preferably compressed air. instead of by hand, which gun may be filled with an appreciably larger dosage of amalgam than the known gun, so that a large cavity may be filled, too, without the gun having to be refilled, while the gun simultaneously compacts these larger doses ofamalgam.

This object is achieved according to the invention by the fact that the amalgam gun housing comprises a filler tube, in which tube a plunger is movably mounted. The plunger is provided with a traversing piston rod, one end of which is connected to a flexible rod supporting the plunger, which flexible rod is movably mounted inside the filler tube. Centrally on the traversing rod is mounted a piston within an air cylinder. The other end of the piston rod supports a second plunger whose diameter is larger than the diameter of the piston rod, but smaller than the diameter of the piston. The cylinder space in which the piston is adapted to move is bounded on the one end by the headwall of the cylinder, to which the filler tube connects, and on the other hand by a transverse wall mounted in side the cylinder and having a centrally disposed orifice. The cylinder is connected to a source of pressure medium at the side of the transverse wall via the annular orifice. The piston rod moves through the centrally disposed orifice in the transverse wall. The distance between the piston and the second plunger being adapted to the length of the cylinder space in such a way that when the piston is entirely or nearly entirely displaced to the aforesaid headwall, the second plunger will seal the centrally disposed orifice in the transverse wall. There is an outlet orifice for the pressure medium in the cylinder wall of the cylinder space, which orifice is just passed by the piston when the piston has reached its final position near the headwall.

The amalgam is thus transferred to the cavity by the admission of compressed air or the like. The gun is previously filled with the desired quantity of amalgam, which quantity may be chosen by the dentist. After filling the cavity the compressed air is still connected to the gun, but can no longer enter the cylinder space. In the final position of the piston, the firstmentioned plunger protrudes beyond the mouth of the filler tube with a small part of its length, on account of which the amalgam is compacted. By pressing the gun against the molar or tooth by hand, the plunger is forced to return inwardly without any interference by the compressed air, since this has disappeared from the cylinder space through the orifice in the cylinder wall.

By the return of the plunger the piston passes the orifice again, releasing the second plunger from the centrally disposed opening in the transverse wall, causing the cylinder space to be reconnected with the compressed air and driving the first plunger to the outside once more. by this arrangement a kind of vibrating effect is produced on the amalgam which is properly compacted in this way.

Further features and advantages of the invention will become apparent from the description following hereinafter with reference to a diagrammatic drawing.

BRIEF DESCRIPTION OF THE DRAWings FIG. 1 is a longitudinal section through the gun with retracted piston, the separately shown filler tube should be considered as connected to the cylinder.

FIG. 2 is a similar longitudinal section with extended piston.

DETAILED DESCRIPTION OF THE DRAWINGS The gun according to the invention comprises a cylinder 1 which is connected at one end to an airhose 2 through which the compressed air is supplied. It is understood that in or in front of this hose there is a valve provided (not shown in the drawing).

The filler tube is indicated with 3 and connects to a headwall 4 of the cylinder 1. In the cylinder is movably mounted a piston 5 with a transversing piston rod indicated with 6a and 6b.

The piston rod 6a is connected to a flexible rod 7 which supports a plunger 8 at the other end, said plunger being movable in the filler tube 3 in a sealing way. The rod 7 has to be flexible to be able to follow the curve in the filler tube 3. The plunger 8 has a somewhat bulbous front face which is adapted to the outer surface ofthe stopping to be applied.

The piston rod 6a furthermore should have an adjustable length which makes it possible to adjust the final position of the plunger 8 relative to the end of the filler tube 3 in order to compensate for the length of the rod 7 which varies in use. These adjusting means are not shown in the drawing.

The piston rod 6b extends through a centrally disposed orifice 9 in a transverse wall 10 and is provided with a second plunger 11 whose diameter is a many times smaller than the diameter of the piston 5. This second plunger 11 is guided in a second cylinder 12 which is concentrically arranged within the first cylinder 1 and is connected therewith via radial ribs 13.

This second cylinder, at one end, terminates just in front of the transverse wall 10, while at the other end it is deflected and connected to the atmosphere.

The centrally disposed orifice 9 is so large that it fits in a sealing way, for instance via an O-ring not shown in the drawing, around the plunger 11, see FIG. 2.

In the wall of the cylinder 1 an orifice 14 is provided in a predetermined location.

In the position of the piston 5, shown in FIG. 1, the plunger 8 is in its most rearward position. The amalgam is now passed by hand or in another way in the end of the filler tube 3, the space available for the amalgam is much larger than in the known guns.

Subsequently, the end of the tiller tube is positioned over the cavity to be filled, while the supply valve of the compressed air is opened. This compressed air is fed to the righthand side of the piston 5 via the centrally disposed orifice 9 around the piston rod 6b. This causes the piston 5 to move from the position of FIG. 1 to the left, causing the amalgam to ble for compressed air to act on the piston. In this position of 5 the piston 5, the plunger 8 protrudes from the filler tube 3 with a part of its length, see the position of the plunger 8 indicated with dotted lines in FIG. 1, on account of which the amalgam has been compacted. Inasmuch as the end of the filler tube is pressed on the molar or tooth by hand, the plunger 8 is forced to retract, so that the orifice 14 is closed again, while the orifice 9 is opened again. The compressed air will force the piston to the left again, etc. In this way the amalgam is compacted by tamping.

In addition to this there is a release valve provided in the wall of the cylinder 1, which release valve 15 may be pressed by the thumb in order to let the compressed air escape into the atmosphere, if necessary.

In addition this the gun is provided with means for a step by step movement of the piston, so that only very small quantities of amalgam are transferred into the cavity. These means comprise, for example, a rod 16 which extends from the right-hand side of the second plunger 11 and is guided at the rearmost end by an element 17. There is a row of triangular teeth 18 on two opposed sides of this rod 16, the rows being staggered over half a pitch length with respect to each other. The perpendicular sides of the teeth are directed forwards.

The teeth 18 of each row are adapted to mate with pins 19, said pins being coupled to each other in vertical direction outside the cylinder 1. These pins are adapted to be moved upward and downward in sealed orifices in the wall of the cylinder 1 and in the wall of the cylinder 12.

In the position shown in FIG, 1, one of the upper teeth 18 rests against the lowermost side of the uppermost pin 19, because of which the piston 5 is prevented from moving to the left.

By pressing the lowermost pin 19 upwards, the topmost tooth is released, enabling the piston to move half a tooth pitch to the left, viz until the next lower tooth contacts the lower pin 19. By alternatively pressing the upper and lower pin downwards and upwards respectively, the piston is forced to move forwards step by step. Not until the end of its stroke the gun is capable ofperforming its tampling compressing action.

The pins 19 will preferably be actuated by springs in upward direction, so that in the usual position the lower pin 19 will always be engaged with a tooth of the lowermost toothed rack. It is then possible for the piston to be moved step by step by intermittently pressing the pins downwards with the fingers. The spring, not shown in the drawing, is adapted to move the pins upwards again.

It will be understood that the gun according to the invention may be changed in various ways where the construction is concerned. It is possible, for instance, to connect the airhose laterally to the cylinder 1, so that the cylinder 12 need not be goosenecked and may be connected to the atmosphere at the rearmost end. In that case, the pins 19 need not extend through the cylinder 1, but only through the elongation of the cylinder 12.

lclaim:

I. An amalgam gun for filling a tooth cavity with amalgam comprising a cylinder having a first end wall and a transverse wall spaced from the first end wall, a tube mounted on the first end wall of the cylinder, a plunger rod movably mounted inside the tube an amalgam plunger mounted at one end of the plunger rod remote from the cylinder, the amalgam plunger together with one end of the tube forming a distal, outward opening storage chamber for accommodating a quantity of amalgam, a piston movably mounted in the cylinder, a piston rod connected to the piston and extending in opposite axial directions therefrom and terminating in first and second ends, the first end of the piston rod being connected to the plunger rod, the second end of the piston rod extending through a fluid inlet orifice in the transverse wall, a valve plunger mounted on the second end of the piston rod for movement thereby into and out of sealing relationship with the inlet orifice, a fluid exhaust port in a cylinder wall near the first end wall, whereby fluid flows from the cylinder when the piston passes and thereby opens the exhaust port, a source of pressure fluid supplied to the inlet orifice, the length of the piston rod between the piston and the valve plunger being adapted to length of the cylinder between the exhaust port and the transverse wall so that, when the piston just passes the exhaust port, the valve plunger seals the inlet orifice,

2. An amalgam gun according to claim 1, characterized in that the valve plunger is guided by a second cylinder which is concentrically arranged within the first cylinder, which second cylinder is connected with the atmosphere at one end, and, via a cylindrical space between the two cylinders, with the source of pressure medium at the other end.

3. An amalgam gun according to claim 2, characterized in that the cylindrical space is adapted to be connected with the atmosphere via a controllable, normally closed, valve.

4. An amalgam gun according to claim 1, characterized in that the gun is provided with means connected to the valve plunger for permitting step by step movement of the first plunger with respect to the filler tube.

5. An amalgam gun according to claim 4, characterized in that the means are formed by a further rod which connects to the valve plunger, on which further rod are provided opposed series of teeth which are staggered with respect to each other and are adapted alternatively to cooperate with one of two pins engaging the teeth, said pins being coupled together.

6. The amalgam gun according to claim 5, characterized in that the coupled pins are spring loaded in one direction.

7. A tooth cavity filling material gun for holding, discharging and packing a packable filling material comprising: a tube, a plunger positioned within the tube for reciprocal motion therein between first and second longitudinally spaced positions, a distal end of the plunger together with a distal end of the tube forming a chamber for holding a quantity of material, a cylinder mounted at an opposite end of the tube, a piston disposed in the cylinder and connected to the plunger, first valve means connected to the cylinder for admitting fluid under pressure when the piston is in a position within the cylinder which corresponds with a first position of the plunger, and second valve means connected to the cylinder for releasing fluid from the cylinder when the piston is in a second posi tion which corresponds with a second position of the plunger.

8. The gun according to claim 7 wherein the first valve means comprises a piston rod extending from the piston through an orifice in an end of the cylinder and a second plunger connected to the piston rod remote from the piston.

9. The gun according to claim 7 wherein the second valve means comprises an opening in a wall of the cylinder remote from an end of the cylinder remote from the first valve means.

10. The gun according to claim 7 further comprising step by step limit means connected to the piston for permitting step by step movement of the piston to advance the plunger toward a distal end of the tube and further comprising movable detent means mounted adjacent the limit means for permitting incremental movement of the limit means, piston and plunger upon sequential displacement of the detent. 

1. An amalgam gun for filling a tooth cavity with amalgam comprising a cylinder having a first end wall and a transverse wall spaced from the first end wall, a tube mounted on the first end wall of the cylinder, a plunger rod movably mounted inside the tube an amalgam plunger mounted at one end of the plunger rod remote from the cylinder, the amalgam plunger together with one end of the tube forming a distal, outward opening storage chamber for accommodating a quantity of amalgam, a piston movably mounted in the cylinder, a piston rod connected to the piston and extending in opposite axial directions therefrom and terminating in first and second ends, the first end of the piston rod being connected to the plunger rod, the second end of the piston rod extending through a fluid inlet orifice in the transverse wall, a valve plunger mounted on the second end of the piston rod for movement thereby into and out of sealing relationship with the inlet orifice, a fluid exhaust port in a cylinder wall near the first end wall, whereby fluid flows from the cylinder when the piston passes and thereby opens the exhaust port, a source of pressure fluid supplied to the inlet orifice, the length of the piston rod between the piston and the valve plunger being adapted to length of the cylinder between the exhaust port and the transverse wall so that, when the piston just passes the exhaust port, the valve plunger seals the inlet orifice.
 2. An amalgam gun according to claim 1, characterized in that the valve plunger is guided by a second cylinder which is concentrically arranged within the first cylinder, which second cylinder is connected with the atmosphere at one end, and, via a cylindrical space between the two cylinders, with the source of pressure medium at the other end.
 3. An amalgam gun according to claim 2, characterized in that the cylindrical space is adapted to be connected with the atmosphere via a controllable, normally closed, valve.
 4. An amalgam gun according to claim 1, characterized in that the gun is provided with means connected to the valve plunger for permitting step by step movement of the first plunger with respect to the filler tube.
 5. An amalgam gun according to claim 4, characterized in that the means are formed by a further rod which connects to the valve plunger, on which further rod are provided opposed series of teeth which are staggered with respect to each other and are adapted alternatively to cooperate with one of two pins engaging the teeth, said pins being coupled together.
 6. The amalgam gun according to claim 5, characterized in that the coupled pins are spring loaded in one direction.
 7. A tooth cavity filling material gun for holding, discharging and packing a packable filling material comprising: a tube, a plunger positioned within the tube for reciprocal motion therein between first and second longitudinally spaced positions, a distal end of the plunger together with a distal end of the tube forming a chamber for holding a quantity of material, a cylinder mounted at an opposite end of the tube, a piston disposed in the cylinder and connected to the plunger, first valve means connected to the cylinder for admitting fluid under pressure when the piston is in a position within the cylinder which corresponds with a first position of the plunger, and second valve means connected to the cylinder for releasing fluid from the cylinder when the piston is in a second position which corresponds with a second position of the plunger.
 8. The gun according to claim 7 wherein the first valve means comprises a piston rod extending from the piston through an orifice in an end of the cylinder and a second plunger connected to the piston rod remote from the piston.
 9. The gun according to claim 7 wherein the second valve means comprises an opening In a wall of the cylinder remote from an end of the cylinder remote from the first valve means.
 10. The gun according to claim 7 further comprising step by step limit means connected to the piston for permitting step by step movement of the piston to advance the plunger toward a distal end of the tube and further comprising movable detent means mounted adjacent the limit means for permitting incremental movement of the limit means, piston and plunger upon sequential displacement of the detent. 